Citation

Abstract

An investigation has been conducted with the two-fold purpose
of producing very high Mach number shock waves and studying their
interaction with an external magnetic field parallel to the shock front.
By means of the technique of electromagnetic driving, stable reproducible, outward-going cylindrical shock waves in the Mach number
range from 20 to 100 have been produced and studied.

Theory predicts fundamental differences between the interaction
of a magnetic field with a shock moving into a highly conducting
fluid and the interaction of a field with a strong gas-ionizing shock.
In the former case a true mhd shock is produced. In the latter the
field interacts directly only with the piston and the shock remains
an ordinary one. The effect of a conducting wall surrounding the
chamber also differs substantially in the two cases.

Detailed experiments have been carried out on gas-ionizing
shocks. While the overall motion is very nearly that predicted by the
theory, anomalies have arisen in the details of the flow and are
explained in a qualitative manner.

Methods of producing sufficient initial conductivity to obtain a
thin magnetohydrodynamic shock are discussed, together with some
preliminary experiments along these lines.